Considering a new dive computer..

[RayfromTX]

I compare that sentiment to telling someone they shouldn't buy a Porsche unless they intend to road race with it. The difference is that the cost of the Perdix or Teric is still a small part of the overall cost of diving.

 

[dmaziuk]

I have to say not being locked out of your computer can be a pretty sweet advantage!!

Wrong: rec computers lock you out if you skip mandatory decompression. The only scenario where skipping mandatory decompression is a "sweet advantage" is better bent than drowned.

 

[loosenit2]

Wrong: rec computers lock you out if you skip mandatory decompression. The only scenario where skipping mandatory decompression is a "sweet advantage" is better bent than drowned.

It is not always that simple, there are numerous reasons a computer may lock you out. For example, my daughter has a Suunto Cobra 3. On the second dive of the day she messed up and put it into gauge mode rather than dive mode. We worked through that because we had checked NDL limits prior to dive and stayed within them for the dive. We finished that dive at 1200 and went out for a dive the next day at 0830 to find the computer still locked out, it had imposed a 24 hour lock out. That is a 19:30 SI between dives, her tissues were clear, even using ultra conservative DAN no fly times she could have flown, but computer was locked out for 24 hours. Thank goodness I had a backup computer for her to use.

My point is some lockouts are earned for missed deco, some don’t make any sense at all, putting human decision making into the process is not a bad thing.

 

[dmaziuk]

My point is some lockouts are earned for missed deco, some don’t make any sense at all, putting human decision making into the process is not a bad thing.

In my experience as "the it professional": bet on luser error, you'll win 99% of the time. Case in point...

 

[loosenit2]

In my experience as "the it professional": bet on luser error, you'll win 99% of the time. Case in point...

Ok..but what is your point in regard to the discussion? You asserted that computer lockouts occur when you miss deco; I showed an example when that is not the case. Just because a user causes an error does not mean that a computer should necessarily lock out....Shearwater has decided to leave that decision to the trained scuba diver who is ultimately making the decision for themselves.

 

[broncobowsher]

Skipping the normal Scubaboard tangent (that will likely be continued by the next person posting here and thereby am going to pre-call them an idiot)…

To the OP, yes a Shearwater is a very good choice. Absolutely nothing wrong with that choice. But as the idiot below me will point out, there is a rabbit hole you can go jump in instead.

 

[Ben_3]

Hi @Ben_3

Start out by reading about Buhlmann ZH-L16C with gradient factors, run on Shearwaters, and PZ+, run on Aqua Lungs. Buhlmann is adjustable over a very wide range from very conservative to very liberal. PZ+ is actually a proprietary version of Buhlmann that is middle of the road/moderate in the spectrum from conservative to liberal. The Shearwaters offer 3 presets as well as custom GFs. The three presets are 45/95. 40/85, and 35/75. The NDL time is controlled by the second number, called the GF high. Below, is a table comparing 1st, clean dive NDLs on air for the 3 Buhlmann presets and PZ+. This does not tell you how the computers handle repetitive dives, only the 1st dive. Buhlmann tends to be more conservative on the 1st dive and relatively more liberal on repetitive dives.

There are many additional decompression algorithms you might want to learn about if you consider other computers. In the meantime, there is nothing wrong with your i300C, running PZ+. I would be inclined to get some more experience and learn more about the computers you are considering before spending the money for a new computer. Best of luck and good diving.

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Thanks for the info very interesting, I will definitely read up on these algorithms shortly. I also have to get a good understanding of playing with the different presets or custom GFs and why a diver would do so. I have homework to do.

 

[RayfromTX]

You do, however as a beginning rec diver, the knowledge you seek is a nice thing to have but not required. Understanding how the computer works and learning the user interface is more important than learning about the algorithm or even the gradient factors. Download the manual and get a feel for it even before you make the purchase decision. Shearwater does a pretty good job with their manuals relative to most of the companies out there.

 

[Ben_3]

I compare that sentiment to telling someone they shouldn't buy a Porsche unless they intend to road race with it. The difference is that the cost of the Perdix or Teric is still a small part of the overall cost of diving.

It's a small part but still a big investment. I'm not a car guy but everyone enjoys luxury even if you dont use it to the max

 

[dmaziuk]

Ok..but what is your point in regard to the discussion? You asserted that computer lockouts occur when you miss deco; I showed an example when that is not the case.

Because when every shearwater sold comes with The Dad Who Knows Better built-in, your example will make a perfectly good argument. Until then what you should consider is not being there: your daughter comes up from a dive and realizes her computer did not compute her accrued gas loading correctly. You are not there to guesstimate the conservatism for the subsequent dives, and she is not trained to do so herself. What would you rather she does next:
a) keep diving like nothing's the matter, or
b) sits out the rest of the day, perhaps reading up on deco theory and use of tables?